Tristar MPPT 60 and Trojan T-105 Batteries

Kentsun
Kentsun Registered Users Posts: 11 ✭
in Grid Tie and Grid Interactive Systems #1
Hi
I wonder if anyone can help me out here.

I have just bought a Morningstar Tristar MPPT 60 controller to use with my existing bank of batteries, 6 x Trojan T-105's wired in series parallel to give a total rating of 675 Ah @12v.

The Trojan Data sheet only gives the following information regarding charging, A daily charge of 14.8v, Float voltage of 13.2v and a equalize voltage of 15.5v.

I know there is a custom setting available on the controller, but i'm a little confused about the settings, such as how long should the batteries be held at 14.8v before dropping off to a lower absorption voltage, and finally down to float.

I realise that all the time that a substantial load is being pulled from the batteries then the charge voltage will remain high, but what I would like to set is a suitable charging regime for a No Load situation.

Looking at the parameters available when setting a custom mode things become a little daunting, so if anyone has set their own Custom Settings for Trojan Batteries and is happy with the results I would be interested to hear what settings were used.

One other thing, in order to create a custom setting, would I have to use the RS232 port?, it's not a problem as I fitted a cable during installation, and have a RS232 to Ethernet adaptor which can easily be hooked up at anytime.

Thanks In Advance
· Share on Twitter

Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #2
    Re: Tristar MPPT 60 and Trojan T-105 Batteries

    We can make this easy: 14.8 Volts is the Absorb Voltage. Three stage charging: Bulk (as much current as available to raise the Voltage), Absorb (sustain high Voltage with diminishing current), and Float (sustained lower Voltage with current fluctuating as per load demand).
    I realise that all the time that a substantial load is being pulled from the batteries then the charge voltage will remain high, but what I would like to set is a suitable charging regime for a No Load situation.

    Nope. The Voltage is set by the charge stage. The current will fluctuate by load demand and may pull the Voltage low if it exceeds the charge source's ability to supply power.

    Better?
    · Share on Twitter
  • Kentsun
    Kentsun Registered Users Posts: 11 ✭
    #3
    Re: Tristar MPPT 60 and Trojan T-105 Batteries

    Hi
    Thank you for your reply, So basically set the Absorption voltage to 14.8v and ignore any times, leave "Enable Absorption Extensior" as it is, currently set at 12.5v, and just set the Float Voltage to 13.2v ?
    · Share on Twitter
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #4
    Re: Tristar MPPT 60 and Trojan T-105 Batteries

    I would time how long it stays in Absorb vs. what the current is. You don't want to remain in Absorb once the current is down below 3%.

    This is one reason why Outback and MidNite controllers are better: the count up/down timer and End Amps functions. The new WhizBang battery monitor that integrates with the Classic is the best idea (actually turn off Absorb by SOC).
    · Share on Twitter
  • Kentsun
    Kentsun Registered Users Posts: 11 ✭
    #5
    Re: Tristar MPPT 60 and Trojan T-105 Batteries
    Cariboocoot wrote: »
    I would time how long it stays in Absorb vs. what the current is. You don't want to remain in Absorb once the current is down below 3%.

    Hmm, That could be tricky as I intend to run a freezer over the summer months when there are more daylight hour's, so the current being drawn will fluctuate, maybe taking some readings with a steady load might give an idea of how long the Aborb time should be.
    · Share on Twitter
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #6
    Re: Tristar MPPT 60 and Trojan T-105 Batteries
    Kentsun wrote: »
    Hmm, That could be tricky as I intend to run a freezer over the summer months when there are more daylight hour's, so the current being drawn will fluctuate, maybe taking some readings with a steady load might give an idea of how long the Aborb time should be.

    Yes you have to make allowances for any large loads operating at the same time.
    · Share on Twitter
  • Kentsun
    Kentsun Registered Users Posts: 11 ✭
    #7
    Re: Tristar MPPT 60 and Trojan T-105 Batteries

    Ok Thank you, well if there is any sun tomorrow (You've probably seen the weather in the UK!!) I'll take some measurements and see if I can work out some timings.
    · Share on Twitter
  • DMJ72
    DMJ72 Solar Expert Posts: 131 ✭✭
    #8
    Re: Tristar MPPT 60 and Trojan T-105 Batteries
    Kentsun wrote: »
    ...One other thing, in order to create a custom setting, would I have to use the RS232 port?, it's not a problem as I fitted a cable during installation, and have a RS232 to Ethernet adaptor which can easily be hooked up at anytime.

    Thanks In Advance

    No RS232 port needed, just set the dip switches for custom settings, then use the MSVIEW software to enter the settings (via the LAN)
    · Share on Twitter
  • Kentsun
    Kentsun Registered Users Posts: 11 ✭
    #9
    Re: Tristar MPPT 60 and Trojan T-105 Batteries

    Hi, Thanks for the reply.

    Well I managed to screw things up, I noticed that there were software updates, so thought I would update the firmware before applying any changes, (Big Mistake)... as the absorb voltage when I looked at it this morning was at 15.2v, which would be about right for the preset voltage, 14.7v + temp compensation @ 10 degrees C, 5mv per cell = 30mv and 15 degrees below 25 Degrees = 450mv + 14.7 = 15.15v, the problem was that the log showed that the batteries had been held at this voltage for over 3 hours, and apart from the controller there has been no load and I know that they were at full charge yesterday evening.

    Anyway, I think I need to start a new thread to find out if there is anyway to restore the factory settings, or if it's a return job, will outline the problems in the new thread
    · Share on Twitter

Categories